1. Field of the Invention
This invention relates to locks and is particularly although not exclusively applicable to locks for utility articles such as refuse bins which have a lift-off lid or cover within which a refuse container is housed mounted on a base, the lock or locks being provided for securing the cover to the base to prevent unauthorised removal. One such refuse bin is described and illustrated in co-pending U.S. patent application Ser. No. 690,949 filed 14th Jan. 1985 assigned to the Assignees of the current application.
2. Background Prior Art
U.K. Pat. No. 1584072 discloses a locking mechanism having at least one locking bolt adapted for guided linear movement in the housing, the bolt being provided on one longitudinal side with a plurality of spaced teeth, the centre lines of the teeth being at an angle of ten to eighty degrees to each side, a key adapted for guided linear movement through a key hole perpendicular to said bolt and having matching teeth in its side edge at a matching angle, the bolt being arranged to be moved when the teeth of the key are meshed with those of the bolt upon linear movement of the key through the key hole.
U.K. Pat. No. 2066345 discloses a similar lock and key arrangement in which a lock has a housing in which one or two bolts are mounted for sliding movement between a locking position and an un-locked position. Each of the two opposing faces of the bolts has allochirally arranged patterns of alternate lines and groove extending obliquely across the bolts. The housing has a key hole extending therethrough in which the shaft of the key is slidable. Opposite edges of the shaft have alternate lands and grooves complimentary respectively to corresponding lands and groove of latch bolts. To withdraw the bolts, the key is slid inwardly so that successive grooves and lands on it engage successively the corresponding patterns on the bolts to cam them inwardly.
U.K. Pat. No. 1243817 discloses a lockable umbrella holder having a lockable flap provided with locking means consisting of a lock having a slot for receiving a suitable key, a latch bolt slidably mounted in the body of the lock and biassed to an extended position wherein a portion of the latch bolt projects from the body, the latch bolt having a projecting pin which extends into the path of the key in the slot so that when the key is inserted into the slot it engages the pin and so that further depression of the key into the slot causes movement of the pin and thus retraction of the latch bolt from its extended position to release the lock.
U.K. Pat. No. 1243819 shows a modification of the latter arrangement in which the lock comprises a body having a slot for receiving a suitable key, a bolt slidably mounted in the body for movement transverse to the path of the key in the slot and biassed to a position wherein a portion thereof projects from the body, the bolt having a projecting pin extending into the path of the key in the slot enabling a suitable surface of the key to engage the pin and cause movement thereof thus retracting the bolt from its extended position.
All the above locking arrangements rely on relatively complicated components which require to be manufactured to a high degree of precision in order to achieve successful operation. While such arrangements may be satisfactory in clean and dry condition, they would not be satisfactory for use on refuse bins placed in the street and other public places and exposed to dirt, wet and relatively hostile environments.
It is an object of the present invention to provide a lock of relatively simple components which whilst preserving said satisfactory degree of security also is so constructed that dust, dirt and damp are unlikely to impede its operation and which is also capable of relatively cheap and simple manufacture.